A striking instrument and struck object monitoring system including at least two shutterable camera units which view a field of view each of which cameras receives light patterns from each and every one of a plurality of contrasting areas on the instrument and the object in rapid successive...http://www.google.fr/patents/US5803823?utm_source=gb-gplus-shareBrevet US5803823 - Method and apparatus to determine object striking instrument movement conditions
Method and apparatus to determine object striking instrument movement ...
